//
//  CalculatorBrain.h
//  Calculator
//
//  Created by nhieu nguyen on 6/28/13.
//  Copyright (c) 2013 nhieu.nguyen. All rights reserved.
//

#import <Foundation/Foundation.h>

@interface CalculatorBrain : NSObject

// The - means this is an instance method ( instances of this class respond to it).
- (void)pushOperand:(double)operand;
- (double)performOperation:(NSString *)operation;

@end
